Not sure how I missed this post. 
The different behavior is based on the manufacturer or integration’s implementations. When you turn the light off, does it automatically set the level to 0%? If not, you might use Variables to store the level value when the switch is turned off, and then create a rule to send the setLevel command with the variable as the argument, then add rule to dashboard, so you can tap it to dim the light to the previous state. (Assuming the setLevel will turn the light on but it’s based on the manufacturer’s implementation again.)